A 2010 study of mitochondrial DNA of the spoonbills by Chesser and colleagues found that the roseate and yellow-billed spoonbills were each other's closest relatives, and the two were descended from an early offshoot from the ancestors of the other four spoonbill species.
The Yellow Book standards help auditors hold the organizations they audit accountable. GAGAS contains requirements relating to ethics, independence, auditorsâ professional judgment and competence, quality control, performance of the audit, and reporting.
The Yellow Book is for use by auditors of government entities, entities that receive government awards, and other audit organizations performing Yellow Book audits. View the Current Yellow Book.1  View the Current Yellow Book. 2  Listen to Our Yellow Book Podcast.ellow Book revisions undergo an extensive, deliberative process, including public comments and input from the Yellow Book Advisory Council. GAO considers all Yellow Book comments and input from the Yellow Book Advisory Council in finalizing revisions to the standards.